Knife sharpener



FIG. 1 is a perspective view taken from the front, top, and right side of a knife sharpener in accordance with the new design.

FIG. 2 is a front view of the knife sharpener of FIG. 1.

FIG. 3 is a rear view of the knife sharpener of FIG. 1.

FIG. 4 is a right side view of the knife sharpener of FIG. 1.

FIG. 5 is a left side view of the knife sharpener of FIG. 1.

FIG. 6 is a top plan view of the knife sharpener of FIG. 1; and,

FIG. 7 is a bottom view of the knife sharpener of FIG. 1.

The broken lines shown in the drawings illustrate portions of the knife sharpener that form no part of claimed design. 

CLAIM The ornamental design for a knife sharpener, as shown and described. 